Substance IT-62-B and medicinal composition containing the same

ABSTRACT

A substance IT-62-B represented by the following formula (1): ##STR1## a production process thereof, a medicinal composition comprising the compound as an active component, and methods of treating an infectious disease caused by bacteria and a tumor, in which such a substance is administered. 
     The compound according to the invention has good antibacterial activities against gram-positive bacteria and some of gram-negative bacteria, and also possesses excellent antitumor activities against tumors such as human nasopharyngeal carcinoma, and is hence useful as a medicine.

TECHNICAL FIELD

The present invention relates to a new substance IT-62-B, a productionprocess thereof, a medicinal composition containing such a substance andmethods of treating an infectious disease caused by bacteria and atumor, in which such a substance is administered.

BACKGROUND ART

It has heretofore been known that microorganisms produce varioussubstances each having wide features from the viewpoint of chemicalstructure, and pharmacological activities such as antibacterialactivities and antitumor activities.

Accordingly, it is an object of the present invention to provide asubstance having far excellent pharmacological activities by usingmicroorganisms.

DISCLOSURE OF THE INVENTION

In view of the foregoing circumstances, the present inventors haveisolated many microorganisms from natural soils to retrieve theircapability of producing substances having useful pharmacologicalactivities. As a result, it has been found that a Streptomyces sp.strain IT-62 belonging to genus Streptomyces produces a novel substanceIT-62-B exhibiting excellent antibacterial activities and antitumoractivities, thus leading to completion of the present invention.

TAN-1120 has been reported as a streptomyces-produced substance having astructure similar to that of the compound according to the presentinvention (Japanese Patent Application Laid Open No. 288892/1990).However, the substance of the present invention is a novel compoundhaving a structure that oxazolidine ring has been additionallyring-condensed.

Namely, the present invention is directed to a substance IT-62-Brepresented by the following formula (1): ##STR2##

The present invention is also directed to a process for producing thesubstance IT-62-B, which comprises culturing a microorganism belongingto genus Streptomyces and having capability of producing the substanceIT-62-B to produce and accumulate such a compound in the culture fluidand to separate the compound.

The present invention is further directed to a medicine, anantibacterial agent and an antitumor agent each comprising the substanceIT-62-B as an active component.

The present invention is still further directed to a medicinalcomposition comprising the substance IT-62-B and a pharmaceuticallypermissible carrier.

The present invention is yet still further directed to methods oftreating a bacterial infectious disease and a tumor, which each compriseadministering an effective amount of the substance IT-62-B to a patient.

The present invention is yet still further directed to use of thesubstance IT-62-B for a medicine.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an ultraviolet absorption spectrum of a substanceaccording to the present invention obtained in Example 1.

FIG. 2 illustrates an infrared absorption spectrum of the substanceaccording to the present invention obtained in Example 1.

FIG. 3 illustrates a ¹ H-NMR spectrum of the substance according to thepresent invention obtained in Example 1.

BEST MODE FOR CARRYING OUT THE INVENTION

The substance IT-62-B according to the present invention is representedby the formula (1), and there are isomers based on asymmetric carbonatoms in this compound. However, the present invention includes all ofthese isomers and mixtures thereof. The substance according to thepresent invention may exist in the form of a hydrate, and the presentinvention also include such a hydrate.

The substance IT-62-B according to the present invention can be producedby culturing a strain having capability of producing this substance(hereinafter referred to as "substance IT-62-B-producing strain") undersuitable conditions.

The substance IT-62-B-producing strain include microorganisms belongingto genus Streptomyces. As an illustrative example thereof, may bementioned Streptomyces sp. strain IT-62. This strain is isolated from asoil of the Uigurian province in the People's Republic of China by thepresent inventors, and was deposited as identification of themicroorganism "Strain IT-62", accession number FERM BP-4666 in NationalInstitute of Bioscience and Human-Technology, Agency of IndustrialScience and Technology, Japan on May 13, 1994.

The microbiological characteristics of the strain IT-62 investigated inaccordance with the method described in International Journal ofSystematic Bacteriology, 16(3), 313-340, 1960 is as follows:

(a) Morphology:

Branching of sporulating hyphae: Simple branching.

Form of sporulation: Straight or flexibilis, or sometime hook, sporeform is cylindrical shape.

Number of spores: 10 to 50 or more spores.

Spore surface: Smooth.

Size of spore: 0.5-0.8×0.7-1.1 μm.

Presence of flagellate: Not present.

Presence of sporangia: Not present.

Attachment site of sporophores: Aerial mycelium.

Possession of sclerotium-forming ability: No possession.

(b) Culture characteristics on various media:

Cultural characteristics of strain IT-62 on various media are shown inTable 1. Taxonomic colors were indicated in accordance with "StandardColor Chart A, 1981" under the supervision of The Japan Color ResearchInstitute. Incidentally, more detailed colors were additionally given inparentheses in terms of color codes in accordance with "The ColorHarmony Manual, the fourth edition, 1958" published by ContainerCorporation of America.

                                      TABLE 1                                     __________________________________________________________________________               Growth                                                             Medium     condition                                                                          Aerial mycelium                                                                          Substrate mycelium                                                                     Soluble pigment                                                                       Reverse                           __________________________________________________________________________    Sucrose-nitrate agar                                                                     Poor None       Colorless                                                                              None    Colorless                         Glucose-asparagine agar                                                                  Good None       Vivid reddish                                                                          Orangish                                                                              Vivid reddish                                                orange (6pa˜6pc)                                                                         orange (6pa˜6lc)            Glycerol-asparagine                                                                      Good Whitish˜pale yellow                                                                Olive yellow                                                                           None    Olive yellow                      agar (ISP medium No. 5)                                                                       (2ca)      (2le)            (2le)                             Inorganic salts-starch                                                                   Good Pale yellowish pink                                                                      Strong reddish                                                                         Orangish                                                                              Strong reddish                    agar (ISP medium No. 4)                                                                       (4ca)      orange (5le)     orange (51e)                      Tyrosine agar                                                                            Good Yellowish white (3cb)˜                                                             Light yellowish                                                                        Brownish                                                                              Yellowish brown                   (ISP medium No. 7)                                                                            yellowish gray (2ec)                                                                     brown (3ie)      (3pg, 3ne)                        Oat meal agar                                                                            Good Yellowish gray                                                                           Light reddish                                                                          Orangish                                                                              Light reddish                     (ISP medium No. 3)                                                                            (2cb˜1ec)                                                                          orange (5lc)     orange (4ne)                      Yeast extract-malt                                                                       Good Whitish, scant                                                                           Strong reddish                                                                         Orangish                                                                              Strong reddish                    extract agar               orange (6ne)     orange (6ne)                      (ISP medium No. 2)                                                            Nutrient agar                                                                            Moderate                                                                           Whitish, scant                                                                           light reddish                                                                          Orangish                                                                              light reddish                                                orange (5lc)     orange (4ic)                      BENNET'S agar                                                                            Good None       Vivid red (61/2pc)                                                                     Orangish                                                                              strong red (6pc)                  __________________________________________________________________________

(c) Physiological characteristics:

Temperature range for growth: The strain exhibits good growth in thetemperature range of 20°-37° C.

Liquefaction of gelatin (glucose-peptone-gelatin medium, 27° C.):Negative.

Liquefaction of gelatin (simple gelatin medium, 20° C.): Positive.

Coagulation of milk (37° C.): Positive.

Peptonization of milk (37° C.): Positive.

Production of a melanoid pigment: Negative on tyrosine agar (ISP mediumNo.7), peptone-yeast extract-iron agar (ISP medium No.6) andtryptone-yeast extract medium (ISP medium No.1).

Production of hydrogen sulfide medium obtained by adding 0.5% yeastextract to peptone-yeast extract-iron agar (ISP medium No.6)!: Positive.

Hydrolysis of starch (starch-inorganic salt agar, ISP medium No.4):Positive.

Reduction of nitrate (1% potassium nitrate-containing bouillon, ISPmedium No.8): Positive.

Decomposition of cellulose: Negative.

(d) Utilization of carbon sources (Pridham-Gottlieb's medium, ISP mediumNo.9):

This strain utilizes D-glucose, L-arabinose, D-xylose, D-fructose,D-mannitol, D-galactose, soluble starch, dextrin, glycerol and maltose,but not utilize inositol, sucrose, L-rhamnose, raffinose and salicin.

(e) Chemotaxonomy:

The whole cell hydrolysates were analyzed by the high performance liquidchromatography described in "Experimental Method for IdentifyingActinomycetes--Qualitative Analysis, Quantitative Analysis of MycelialComponents by HPLC, pp. 1-8, 1989" edited by The Japan Society forActinomycetes Japan. As a result, LL-diaminopimelic acid was detected.

In view of the fact that the strain according to the present inventionhas the above-described microbiological characteristics, in particular,those characteristics that aerial mycelia having many spore chains areformed, the amino acid in the cell wall hydrolysates containsLL-diaminopimelic acid, and neither flagellate nor sporangia are formed,it is apparent that the strain belongs to genus Streptomyces.Accordingly, this strain was determined to be designated "Streptomycessp. IT-62".

The substance IT-62-B according to the present invention can beproduced, for example, by culturing various substance IT-62-B-producingmicroorganisms belonging to genus Streptomyces such as the strain IT-62or variants thereof in their suitable media, then separating crudeextracts containing the substance of the present invention from theculture media and further isolating the substance IT-62-B from the crudeextracts to purify it.

The culture of the microorganism is basically carried out in accordancewith the culture of the general microorganisms. It is, however,generally preferred to perform the culture under aerobic conditions suchas a shaking culture process by liquid culture or aerobic spinnerculture process.

The medium used in the culture may be some of media so far as itcontains nutrients which can be utilized by the substanceIT-62-B-producing bacteria. Some of various synthetic media,semisynthetic media, natural media and the like may be used. As a carbonsource for the medium, glucose, sucrose, fructose, glycerol, dextrin,starch, molasses, corn steep liquor, organic acids and the like may beused either singly or in any combination thereof; and as a nitrogensource, organic nitrogen sources such as Pharma media, peptone, meatextract, yeast extract, soybean powder, casein, amino acids and urea,and inorganic nitrogen sources such as sodium nitrate and ammoniumsulfate may be used either singly or in any combination thereof. To themedium, sodium salts, potassium salts, magnesium salts, phosphates,heavy metal salts and/or the like may be suitably added if needed.

If foaming is marked during the culture, antifoaming agents, such asvegetable oils, for example, soybean oil and linseed oil, higheralcohols such as octadecanol, tetradecanol and heptadecanol, and varioussilicon compounds may also be suitably added to the medium.

It is preferable to adjust the pH of the medium near to neutrality. Theincubation temperature may preferably be maintained at a temperature forthe good growth of the substance IT-62-B-producing strain, usually20°-37° C., particularly preferably about 25°-30° C. The incubation timemay preferably be 4-7 days for both liquid shaking culture and aeratedagitating-culture.

As described above, the various incubation conditions may be suitablychanged according to the kind and nature of the microorganism used,external conditions and the like, and optimum conditions may be selectedfrom and controlled within the above ranges depending thereon.

The separation of the crude extract containing the substance IT-62-Bfrom the culture fluid can be carried out in accordance with the generalmethod for collecting fermentation products. For example, means such assolvent extraction, partition and absorption chromatography andcrystallization may be used either singly or in combination thereof inany suitable order. More specifically, since the substance IT-62-Bproduced by the above culture is principally present in the culturalmycelia, filtration, centrifugation or the like is first performed toseparate a filtrate of the culture fluid and solid mycelia from eachother. The resultant solid mycelia containing the substance IT-62-B areextracted with a solvent such as methanol or acetone to dissolve thesubstance IT-62-B out of the mycelia. Then, the solvent is removed underreduced pressure, whereby a crude concentrate containing the substanceIT-62-B can be obtained. An organic solvent immiscible with water, suchas ethyl acetate, chloroform or butanol is added to this crudeconcentrate to extract the substance IT-62-B with organic solvent. Afterthe thus-obtained solvent layer is added with Glauber's salt todehydrate, the solvent is removed under reduced pressure, whereby acrude extract containing the substance IT-62-B can be obtained. Asneeded, there may be adopted such means as its pH is adjusted withsodium hydroxide or hydrochloric acid, industrial sodium chloride isadded to enhance efficiency of extraction, and the formation of anemulsion is prevented.

In order to isolate and purify the substance IT-62-B from the crudeextract, there may be used usual means for isolation and purification ofa fat-soluble low-molecular weight substance, for example, a variety ofadsorption chromatography on adsorbents such as silica gel, alumina andmacroporous and nonionic adsorption resins, and reversed phasechromatography making use of ODS-bonded silica gel or the like. Ofthese, chromatography on silica gel using chloroform, or a mixed solventsystem such as chloroform/methanol, chloroform/methanol/benzene ortoluene/methanol, as an eluent, and reversed phase chromatography usinga mixed solvent system such as acetonitrile/water or methanol/water inelution are particularly preferred. If further purification is required,the above-described chromatography may be conducted repeatedly or insuitable combination with gel filtration chromatography on SephadexLH-20 (product of Pharmacia AB) using chloroform, methanol or the likeas an eluent, or the like, thereby obtaining the substance IT-62-B withhigh purity.

The identification of the substance IT-62-B during the purificationprocess may preferably be performed by a bioassay using a microorganismon which a growth inhibiting effect is detected by this substance, forexample, Micrococcus luteus ATCC 9341, a method of determining thecytotoxic effect on an established culture cell line (KB cell line)derived from human nasopharyngeal carcinoma and a detecting method usinghigh performance liquid chromatography in combination.

With respect to the pharmacological administration form in the casewhere the substance IT-62-B purified in the above described manner isused as a medicinal composition, there may be used any of oralpreparations such as tablets, capsules, powders, granules, finegranules, solutions, pills, emulsions and suspensions; and parenteralpreparations such as injections, suppositories, ointments, plasters,poultices, aerosols and ophthalmic solutions. The preparations of theseadministration forms can be formulated respectively in accordance withthe conventional formulation methods known by those skilled in the art.

In the case where a solid oral preparation is formulated, it is onlynecessary to add an excipient, and optionally a binder, disintegrator,lubricant, colorant, flavor and/or the like to the active componentaccording to the present invention, and then form the mixture intotablets, capsules, powder, granules, fine granules or the like inaccordance with a method known per se in the art. As examples of theexcipient include lactose, sucrose, starch, talc, magnesium stearate,crystalline cellulose, methylcellulose, carboxymethylcellulose,glycerol, sodium alginate and gum arabic. Examples of the binder includepolyvinyl alcohol, polyvinyl ether, ethylcellulose, gum arabic, shellacand sucrose. Examples of the lubricant include magnesium stearate andtalc. Besides, those conventionally known may be used as the colorant,disintegrator and the like. The tablets may be coated by the well-knownmethod.

In the case where an injection is prepared, it is only necessary to adda pH adjustor, buffer, stabilizer, isotonicity-imparting agent, localanesthetic and/or the like to the active component according to thepresent invention, and prepare the mixture into an intravenous,intramuscular, subcutaneous, intracutaneous and intraperitonealinjection. As the pH adjustor and buffer, may be used sodium citrate,sodium acetate, sodium phosphate and the like. As the stabilizer, may beused sodium pyrosulfite, ethylenediaminetetraacetic acid, thioglycolicacid, thiolactic acid and the like.

A suppository can be prepared by adding a base, and optionally asurfactant and/or the like to the active ingredient according to thepresent invention, and then following a method known per se in the art.As the base, may be used, for example, oil bases such as Macrogol,lanolin, cacao butter, fatty acid, triglycerides and Witepsol (productof Dynamit Nobel Co.).

The amount of the active component according to the present invention tobe incorporated in the above-described preparations of the variousadministration forms may be suitably selected according to dosing route,the age, sex, diseased condition of the patient to be dosed, the kindsof compounds to be incorporated, and other conditions. However, theactive component according to the present invention may be dosed in anamount of generally 0.005-20 mg/day at once or in 2-4 installments.

EXAMPLES

The present invention will hereinafter be described more specifically bythe following Example and Test Examples. However, this invention is notdefined to and by these examples.

Example 1 Production of the substance IT-62-B of the present invention:

(a) Culture process:

One hundred milliliters of a medium (pH 7.2) comprising 0.5% of glucose,2.4% of soluble starch, 0.3% of beef extract, 0.5% of yeast extract,0.5% of peptone, 0.4% of corn steep liquor, 0.002% of cobalt chlorideand 0.4% of calcium carbonate were poured into a 500-ml Erlenmeyerflask, sterilized and then inoculated with one platinum loopful of aStreptomyces sp. strain IT-62 (Accession Number FERM BP-4666) to conductrotary shaking culture at 27° C. for 2 days (220 rpm, 7-cm throw). Then,100 ml of a medium (pH 7.2) comprising 0.5% of glucose, 2.5% of dextrin,2.0% of sesame meal, 0.5% of corn steep liquor, 0.05% of monopotassiumhydrogenphosphate, 0.05% of magnesium sulfate, 0.03% of potassiumchloride and 0.3% of calcium carbonate was poured into a 500-mlErlenmeyer flask and sterilized. Thereafter, the seed culture above wereadded in a proportion of 2% to conduct rotary shaking culture at 27° C.for 5 days (220 rpm, 7-cm throw).

(b) Separation process:

After the culture fluid (40 liters, pH 7.6) obtained in the aboveprocess was collected, centrifuged and filtered, the culture myceliawere extracted twice with acetone (5 liters). The resultant acetoneextract was concentrated under reduced pressure, and the resultantconcentrate was adjusted to pH 8.0 with a diluted aqueous Solution ofsodium hydroxide and then extracted twice with ethyl acetate (2 liters).The fraction extracted with ethyl acetate was concentrated under reducedpressure, and the resultant oily substance (11 g) was dissolved inchloroform (40 ml). Precipitate obtained by further adding n-hexane (120ml) to the solution was washed with n-hexane and then dried, therebyobtaining 2.7 g of a crude extract.

(c) Isolation and purification process:

The above-obtained crude extract was dissolved in chloroform andsubjected to column chromatography on silica gel (Silica Gel 60, 4.1 cmin inner diameter×25 cm in length, product of Merck AG) to effectstepwise elution first with chloroform and then with a mixed solvent ofchloroform/methanol (50:1 and 25:1 v/v). The eluted active fractionswere identified by a bioassay using Micrococcus luteus ATCC 9341 tocollect active fractions containing the substance IT-62-B. Thethus-collected active fractions were distilled, and the residue wasdried over to obtain 155 mg of an oily substance.

Seventy-five milligrams of the thus-obtained oily substance weredissolved in chloroform/methanol (1:1 v/v) to subject the solution togel filtration chromatography (on Sephadex LH-20 (2.0 cm in innerdiameter×92 cm in length), product of Pharmacia AB so as to elute withchloroform/methanol (1:1 v/v). Active fractions containing the substanceIT-62-B were collected, and the solvent was removed from thethus-collected active fraction, thereby obtaining 26 mg of an oilysubstance. The thus-obtained oily substance was dissolved inacetonitrile/water (2:3 v/v), subjected to reversed-phase chromatographymaking use of an ODS-bonded silica gel column on Ultrapack ODS (30-50μm, 1.0 cm in inner diameter×50 cm in length, product of Yamazen-Co.,Ltd.) so as to elute at a flow rate of 1.5 ml/min usingacetonitrile/water (2:3 v/v) as an eluent. The eluted active fractionswere identified by the bioassay and high performance liquidchromatography to collect active fractions containing the substanceIT-62-B. The organic solvent was removed to get the thus-collectedactive fraction, and the residue was then lyophilized, thereby to obtain12 mg of the substance IT-62-B as red powder.

The physico-chemical properties of the thus-obtained substance IT-62-Bwill be described below.

(1) Appearance: Red powder.

(2) Molecular formula:

C₃₉ H₄₇ NO₁₅ (measured by high resolution fast atomic bombardment massspectrometory. As C₃₉ H₄₇ NO₁₅ Na, found: 792.294; calculated: 792.284).

(3) Molecular weight:

769 (measured by fast atomic bombardment mass spectrometory).

(4) Optical rotation:

α!_(D) ²³ +360° (c=0.015, methanol).

(5) Ultraviolet absorption spectrum, in methanol solution, λ_(max) (nm)(ε):

233(33100), 251(23400), 289(6600), 480(11300), 495(11400), 530(6200, sh)(see FIG. 1).

(6) Infrared absorption spectrum, KBr tablet method, ν_(max) (cm⁻¹):

3435, 2970, 2935, 1710, 1620, 1580, 1415, 1285, 1210, 1120, 1035, 995(see FIG. 2).

(7) Nuclear magnetic resonance spectrum:

The values of chemical shifts in a 400 MHz ¹ H-NMR spectrum (FIG. 3) anda 100 MHz ¹³ C-NMR spectrum measured in a deuteriochloroform solutionare shown in Tables 2 and 3, respectively.

                  TABLE 2                                                         ______________________________________                                        Position    .sup.1 H (δ)                                                ______________________________________                                         1          8.01,d,8Hz                                                         2          7.77,t,8Hz                                                         3          7.38,d,8Hz                                                         7          5.27,dd,4,1Hz                                                      8          2.12,dd,15,4Hz, 2.36,dt,15,1Hz                                    10          2.91,d,19Hz, 3.22,dd,19,1.5Hz                                     14          2.44,s                                                            OCH.sub.3 -4                                                                              4.07,s                                                            OH-6        13.94,s                                                           OH-9        4.49,br.s                                                         OH-11       13.23,s                                                            1'         5.60,d,4Hz                                                         2'         1.61,dd,13.5,4Hz, 2.64,td,13.5,4Hz                                 3'         4.61,dd,13.5,4Hz                                                   4'         3.61,s                                                             5'         4.29,q,6.5Hz                                                       6'         1.26,d,6.5Hz                                                       1"         4.74,dd,7,4Hz                                                      2"         1.78,ddd,14,9.5,4Hz, 1.85,ddd,14,7,3Hz                             3"         4.03,m                                                             4"         1.23,d,6Hz                                                         5"         3.48,dq,8,6.5Hz                                                    6"         4.70,d,8Hz                                                         7"         1.31,d,6.5Hz                                                       9"         4.15,d,4.5Hz                                                      10"         2.12,m                                                            11"         3.58,dd,11,7.5Hz, 3.65,dd,11,4.5Hz                                12"         0.98,d,7Hz                                                        ______________________________________                                    

The above positions denote protons situated at the following sites,respectively.

                  TABLE 3                                                         ______________________________________                                        Position .sup.13 C (δ)                                                                         Position                                                                              .sup.13 C (δ)                            ______________________________________                                        1        119.80,d      1'      100.67,d                                       2        135.65,d      2'      28.70,t                                        3        118.36,d      3'      50.41,d                                        4        161.03,s      4'      79.18,d                                         4a      120.95,s      5'      69.51,d                                        5        187.03,s      6'      17.17,q                                         5a      111.38,s      1"      106.53,d                                       6        156.41,s      2"      45.64,t                                         6a      134.14,s      3"      64.38,d                                        7        69.68,d       4"      23.97,q                                        8        35.13,t       5"      80.37,d                                        9        76.61,s       6"      91.03,d                                        10       33.36,t       7"      17.17,q                                        10a      134.64,s      8"      173.18,s                                       11       155.92,s      9"      80.20,d                                        11a      111.21,s      10"     38.02,d                                        12       186.59,s      11"     64.21,t                                        12a      135.55,s      12"     12.44,q                                        13       212.19,s                                                             14       24.87,q                                                              OCH.sub.3 -4                                                                           56.64,q                                                              ______________________________________                                         ##STR3##                                                                       (8) Solubility:                                                           

Easily soluble in methanol, ethanol, acetone, chloroform and dimethylsulfoxide, but hardly soluble in n-hexane, ether and water.

(9) Melting point: 153°-155° C.

(10) High performance liquid chromatography:

A peak is given at a retention time (t_(R)) of 6.9 minutes under thefollowing analytical conditions.

Column: Inertsil ODS-2, 5 μm (4.6 mm inner diameter×150 mm in length,product of GL Science Co, Ltd.).

Mobile phase: Acetonitrile/0.05% aqueous solution of trifluoroaceticacid (50:50 v/v).

Flow rate: 1 ml/min.

Detection: 210 nm, 0.04 a.u.f.s.

Test Example 1:

(1) Determination of antibacterial activities of the substance IT-62-B:

Minimum inhibitory concentrations (MICs) of the compound according tothe present invention against various bacteria were determined inaccordance with the MIC measurement method of Japan Society ofChemotherapy (see journal of Chemotherapy, Vol. 29, No. 1, pp. 76-79,1981). More specifically, Muller-Hinton agar media (product of DifcoCo.) containing the compound according to the present invention atvarious concentrations were used. The test organisms diluted to 10⁶cells/ml, respectively, were inoculated said test organisms having beengrown on the same medium as described above. After incubation at 37° C.for 18 hours, the state of growth of the test organisms was observed totake a minimum inhibitory concentration (MIC, μg/ml), at which thegrowth of the test organism was completely inhibited (in theobservation, it was considered that the growth of the test organism wasinhibited if the number of colonies was 5 or less.). The results areshown in Table 4.

                  TABLE 4                                                         ______________________________________                                        Strain tested         MIC (μg/ml)                                          ______________________________________                                        Staphylococcus aureus Smith                                                                         6.25                                                    Staphylococcus aureus (MRSA)70                                                                      12.5                                                    Staphylococcus aureus (MRSA)92-1192                                                                 12.5                                                    Staphylococcus epidermidis ATCC 12228                                                               25                                                      Enterococcus faecalis IFO 12968                                                                     50                                                      Micrococcus luteus ATCC 9341                                                                        3.13                                                    Micrococcus luteus ATCC 10240                                                                       1.56                                                    Bacillus subtilis ATCC 6633                                                                         3.13                                                    Bacillus subtilis ATCC(rec.sup.+)                                                                   6.25                                                    Bacillus subtilis ATCC(rec.sup.-)                                                                   0.39                                                    Bacillus cereus IFO 3001                                                                            12.5                                                    Escherichia coli NIHJ 100                                                     Escherichia coli IAM 1268                                                                           50                                                      Proteus vulgaris IID OX-19                                                                          >100                                                    Klebsiella pneumoniae ATCC 29665                                                                    >100                                                    Serratia marcescens IFO 12648                                                                       >100                                                    Salmonella typhymurium G-46                                                                         >100                                                    Alcaligenes faecalis IAM 1015                                                                       12.5                                                    Pseudomonas aeruginosa NCTC 10490                                                                   >100                                                    ______________________________________                                    

Test Example 2:

Determination of antitumor activities of the substance IT-62-B:

A. Determination of 50% inhibitory concentration against the establishedculture cell line derived from human nasopharyngeal carcinoma:

A 50% inhibitory concentration (IC₅₀) of the compound according to thepresent invention against an established culture cell line (KB cellline) derived from human nasopharyngeal carcinoma was determined. Morespecifically, the KB cell line (2×10³ cells/ml of medium) was culturedin an Eagle's minimal essential medium supplemented with a 10% calfserum, and 3 ml of this culture medium was incubated in a plastic Petridish to incubate it at 37° C. in a CO₂ -incubator (5% CO₂). Afterovernight incubation, the compound according to the present inventionwas added with the compound diluted from a concentration of 1 μg/ml to aconcentration of 1×10⁻⁶ μg/ml by 10-fold dilution. After incubation for3 days, the cells were torn from the surface of the Petri dish withtrypsin to count viable cell numbers under an optical microscope by adye-exclusion method making use of trypan blue, thereby calculating aconcentration (IC₅₀) exhibiting substantially 50% growth inhibition ascompared with a control. As a result, IC₅₀ was found to be 0.006 μg/ml.

B. Survival effect against murine leukemia P388 cells implantedintraperitoneally:

The antitumor activity of the compound according to the presentinvention was judged by the survival effect against murine leukemia(p388 cells). The three of Male CDF₁ mice (aged 6 weeks) were used astest animals for an administering group and 10 mice for an untreatingcontrol group. Murine leukemia P388 cells (1×10⁶ cells) were implantedintraperitoneally in all the mice. Upon elapsed time of 1 day (the firstday) after the implantation, the substance IT-62-B dissolved in a 3.5%solution of dimethyl sulfoxide in physiological saline was administeredintraperitoneally to the mice of the administering group at a dose of0.25 mg/kg so as to observe survival days of the mice. Percent increasein survival was calculated from the respective survival days thusobtained in accordance with the following equation, and found to be119%. ##EQU1## Results:

As appeared in Test Example 1, the substance IT-62-B according to thepresent invention exhibited good antibacterial activities againstgram-positive bacteria and some of gram-negative bacteria. Besides, asdemonstrated by Test Example 2, the compound according to the presentinvention had the 50% inhibitory concentration (IC₅₀) of 0.006 μg/mlagainst the established culture cell line (KB cell line) derived fromhuman nasopharyngeal carcinoma, and exhibited the percent increase of119% in the survival of the mice in which the murine leukemia P388 cellshad been implanted intraperitoneally. Therefore, the compound exhibitedstrong antitumor activities in both in vitro and in vivo tests.

INDUSTRIAL APPLICABILITY

The substance IT-62-B according to the present invention has goodantibacterial activities against gram-positive bacteria and some ofgram-negative bacteria, and also possesses excellent antitumoractivities against tumors such as human nasopharyngeal carcinoma, and ishence useful as a medicine.

We claim:
 1. A substance IT-62-B represented by the following formula(1): ##STR4##
 2. A process for producing the substance IT-62-B accordingto claim 1, which comprises culturing a microorganism belonging to genusStreptomyces and having capability of producing the substance IT-62-Baccording to claim 1 to produce and accumulate such a compound in theculture fluid and to separate the compound.
 3. The process according toclaim 2 for producing the Substance IT-62-B, wherein the microorganismis a Streptomyces sp. strain IT-62.
 4. A medicine comprising thesubstance IT-62-B as an active component.
 5. The medicine according toclaim 4, wherein the medicine is an agent for treating a bacterialinfectious disease or a tumor.
 6. A medicinal composition comprising aneffective amount of the substance IT-62-B according to claim 1 and apharmaceutically permissible carrier.
 7. The medicinal compositionaccording to claim 6, which is suitable for use in the treatment for abacterial infectious disease or a tumor.
 8. A method of treating abacterial infectious disease, which comprises administering an effectiveamount of the substance IT-62-B according to claim 1 to a patient.
 9. Amethod of treating a tumor, which comprises administering an effectiveamount of the substance IT-62-B according to claim 1 to a patient.